The neutronic calculations and activation behavior of the proposed helium cooled ceramic breeder（HCCB） blanket were predicted for the Chinese Fusion Engineering Testing Reactor（CFETR） design model using the MCNP m...The neutronic calculations and activation behavior of the proposed helium cooled ceramic breeder（HCCB） blanket were predicted for the Chinese Fusion Engineering Testing Reactor（CFETR） design model using the MCNP multi-particle transport code and its associated data library. The tritium self-sufficiency behavior of the HCCB blanket was assessed, addressing several important breeding-related arrangements inside the blankets. Two candidate first wall armor materials were considered to obtain a proper tritium breeding ratio（TBR）. Presentations of other neutronic characteristics, including neutron flux, neutron-induced damages in terms of the accumulated dpa and helium production were also conducted. Activation, decay heat levels and contact dose rates of the components were calculated to estimate the neutron-induced radioactivity and personnel safety. The results indicate that neutron radiation is efficiently attenuated and slowed down by components placed between the plasma and toroidal field coil.The dominant nuclides and corresponding isotopes in the structural steel were discussed. A radioactivity comparison between pure beryllium and beryllium with specific impurities was also performed. After a millennium cooling time, the decay heat of all the concerned components and materials is less than 1？×？10-4 k W, and most associated in-vessel components qualify for recycling by remote handling. The results demonstrate that acceptable hands-on recycling and operation still require a further long waiting period to allow the activated products to decay.展开更多
The scent of receptive females as a signal to reproduction stimulates male mice to olfactory search of a potential breeding partner.This searching behavior is coupled with infection risk due to bacterial contamination...The scent of receptive females as a signal to reproduction stimulates male mice to olfactory search of a potential breeding partner.This searching behavior is coupled with infection risk due to bacterial contamination of the fecal and urine scent marks.We hypothesized that sniffing of female soiled bedding induced the migration of immuno-competent cells into airways as a possible adaptation to breeding-related infection.Using bronchoalveolar lavage in a study on mice,we found the number of leukocytes to be significantly higher in male mice that were provided new portions of soiled bedding daily from female cages,in comparison with male mice that were kept in isolation from female scent.The number of leukocytes in blood was equal in both groups.However,monocytes were fewer in number in male mice exposed to female scent than in male mice isolated from female mice.Scent-induced migration of leukocytes was accompanied by typical behavioral(increased sniffing activity and aggressiveness)and morpho-logical(increase preputial glands and seminal vesicles)responses to olfactory sexual stimulus.展开更多
文摘The neutronic calculations and activation behavior of the proposed helium cooled ceramic breeder（HCCB） blanket were predicted for the Chinese Fusion Engineering Testing Reactor（CFETR） design model using the MCNP multi-particle transport code and its associated data library. The tritium self-sufficiency behavior of the HCCB blanket was assessed, addressing several important breeding-related arrangements inside the blankets. Two candidate first wall armor materials were considered to obtain a proper tritium breeding ratio（TBR）. Presentations of other neutronic characteristics, including neutron flux, neutron-induced damages in terms of the accumulated dpa and helium production were also conducted. Activation, decay heat levels and contact dose rates of the components were calculated to estimate the neutron-induced radioactivity and personnel safety. The results indicate that neutron radiation is efficiently attenuated and slowed down by components placed between the plasma and toroidal field coil.The dominant nuclides and corresponding isotopes in the structural steel were discussed. A radioactivity comparison between pure beryllium and beryllium with specific impurities was also performed. After a millennium cooling time, the decay heat of all the concerned components and materials is less than 1？×？10-4 k W, and most associated in-vessel components qualify for recycling by remote handling. The results demonstrate that acceptable hands-on recycling and operation still require a further long waiting period to allow the activated products to decay.
基金supported by the Russian Foundation for Basic Research(No.08-04-00406)the Heiwa Nakajima Foundation(Japan)。
文摘The scent of receptive females as a signal to reproduction stimulates male mice to olfactory search of a potential breeding partner.This searching behavior is coupled with infection risk due to bacterial contamination of the fecal and urine scent marks.We hypothesized that sniffing of female soiled bedding induced the migration of immuno-competent cells into airways as a possible adaptation to breeding-related infection.Using bronchoalveolar lavage in a study on mice,we found the number of leukocytes to be significantly higher in male mice that were provided new portions of soiled bedding daily from female cages,in comparison with male mice that were kept in isolation from female scent.The number of leukocytes in blood was equal in both groups.However,monocytes were fewer in number in male mice exposed to female scent than in male mice isolated from female mice.Scent-induced migration of leukocytes was accompanied by typical behavioral(increased sniffing activity and aggressiveness)and morpho-logical(increase preputial glands and seminal vesicles)responses to olfactory sexual stimulus.
